/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: StringValueHandler.java,v 1.2.4.1 2005/09/06 11:33:25 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.runtime;

import org.xml.sax.SAXException;

import com.sun.org.apache.xml.internal.serializer.EmptySerializer;

/**
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 * @author Morten Jorgensen
 */
public final class StringValueHandler extends EmptySerializer {

  private StringBuilder _buffer = new StringBuilder();
  private String _str = null;
  private static final String EMPTY_STR = "";
  private boolean m_escaping = false;
  private int _nestedLevel = 0;

  public void characters(char[] ch, int off, int len)
      throws SAXException {
    if (_nestedLevel > 0) {
      return;
    }

    if (_str != null) {
      _buffer.append(_str);
      _str = null;
    }
    _buffer.append(ch, off, len);
  }

  public String getValue() {
    if (_buffer.length() != 0) {
      String result = _buffer.toString();
      _buffer.setLength(0);
      return result;
    } else {
      String result = _str;
      _str = null;
      return (result != null) ? result : EMPTY_STR;
    }
  }

  public void characters(String characters) throws SAXException {
    if (_nestedLevel > 0) {
      return;
    }

    if (_str == null && _buffer.length() == 0) {
      _str = characters;
    } else {
      if (_str != null) {
        _buffer.append(_str);
        _str = null;
      }

      _buffer.append(characters);
    }
  }

  public void startElement(String qname) throws SAXException {
    _nestedLevel++;
  }

  public void endElement(String qname) throws SAXException {
    _nestedLevel--;
  }

  // Override the setEscaping method just to indicate that this class is
  // aware that that method might be called.
  public boolean setEscaping(boolean bool) {
    boolean oldEscaping = m_escaping;
    m_escaping = bool;

    return bool;
  }

  /**
   * The value of a PI must not contain the substring "?>". Should
   * that substring be present, replace it by "? >".
   */
  public String getValueOfPI() {
    final String value = getValue();

    if (value.indexOf("?>") > 0) {
      final int n = value.length();
      final StringBuilder valueOfPI = new StringBuilder();

      for (int i = 0; i < n; ) {
        final char ch = value.charAt(i++);
        if (ch == '?' && value.charAt(i) == '>') {
          valueOfPI.append("? >");
          i++;
        } else {
          valueOfPI.append(ch);
        }
      }
      return valueOfPI.toString();
    }
    return value;
  }
}
